If you get blank pages when trying to access a phar web-page, then you probably have Suhosin on your PHP (like in Debian and Ubuntu), and you need to ad this to your php.ini to allow execution of PHAR archives :

PHAR stores temporary files in either `sys_temp_dir` or the current working directory(CWD).

This is especially important if you're CWD is on a remote file system. Often web server clusters will share a common file system between each web server (using NFS, DFS, etc...). In such scenarios, if you don't set `sys_temp_dir` to a local directory, PHAR will be creating temporary files over the network, which will result in performance and functionality problems.